Relationship between Markers of Gut Barrier Function and Erythrocyte Membrane PUFAs in Diarrhea-Predominant IBS Patients Undergoing a Low-FODMAP Diet

Nutrients. 2024 Aug 14;16(16):2706. doi: 10.3390/nu16162706.

Abstract

Many patients with irritable bowel syndrome (IBS) have a compromised intestinal barrier associated with low-grade inflammation. Polyunsaturated fatty acids (PUFAs) are potential mediators of inflammation: omega-6 PUFAs are pro-inflammatory, while omega-3 PUFAs are antioxidant and anti-inflammatory. Zonulin is a potential biomarker for small intestinal permeability (s-IP). This study investigated the relationship between PUFAs and gastrointestinal (GI) barrier integrity in IBS patients with predominant diarrhea (IBS-D). We evaluated GI barrier function indicators in the urine and bloodstream and erythrocyte membrane PUFA composition in 38 IBS-D patients (5 men, 33 women, 44.11 ± 1.64 years), categorized at baseline by fecal zonulin levels into high (≥107 ng/mL, H-FZ) and normal (<107 ng/mL N-FZ) groups. Evaluations were conducted prior to and following a 12-week diet low in FODMAPs (LFD). At baseline, H-FZ patients had s-IP significantly higher than the reference value, lower n-3 PUFAs levels, and higher n-6/n-3 PUFAs and arachidonic acid (AA) to eicosapentaenoic acid (EPA) ratios than N-FZ. After LFD, H-FZ patients showed significant increases in n-3 PUFAs levels; decreases in n-6 PUFAs, n-6/n-3 PUFAs and AA/EPA ratios; and improved s-IP. The n-6/n-3 PUFAs ratio positively correlated with fecal zonulin levels in all subjects. These findings highlight the relationship between PUFAs and the intestinal barrier, suggesting their role in IBS-D pathophysiology and confirming the positive effects of LFD in managing IBS-D.

Keywords: dietary carbohydrates; fatty acids; fatty acids unsaturated; fermentation FODMAPs; intestinal permeability; irritable bowel syndrome; omega-3; zonulin.

MeSH terms

  • Adult
  • Biomarkers* / urine
  • Cholera Toxin
  • Diarrhea* / etiology
  • Erythrocyte Membrane* / chemistry
  • Erythrocyte Membrane* / metabolism
  • FODMAP Diet
  • Fatty Acids, Omega-3 / analysis
  • Fatty Acids, Unsaturated / analysis
  • Feces / chemistry
  • Female
  • Haptoglobins* / metabolism
  • Humans
  • Intestinal Mucosa / metabolism
  • Irritable Bowel Syndrome* / diet therapy
  • Male
  • Middle Aged
  • Permeability
  • Protein Precursors / metabolism

Substances

  • Haptoglobins
  • zonulin
  • Biomarkers
  • Fatty Acids, Omega-3
  • Fatty Acids, Unsaturated
  • Protein Precursors
  • Cholera Toxin